1. Field of the Invention
The invention relates generally to processing of Job Definition Format (JDF) information and more specifically relates to methods and structures for converting JDF information into command language directives for a printer.
2. Discussion of Related Art
In many printing environments, including print shops (large and small), production printing, and even smaller workgroup environments, it is generally known to create JDF information describing the processing to print a particular print job. JDF is a widely adopted standard specification for providing information (printing parameters) relating to processing of a print job. The JDF information is typically contained in an object/file referred to as a “job ticket” and is associated with the print data for the print job by entries in the job ticket. A JDF job ticket includes any number of JDF elements that specify printing parameters associated with the printing of a particular job. Exemplary of such printing parameters are: one or more resource locators identifying content for the material to be printed, rendering parameters indicating options for rendering various types of objects associated with a print job, layout options indicating, for example, n-up, duplex, and other available print options, etc.
The JDF standards are published by CIP4 (a trade organization) and are readily available at www.cip4.org. In general, JDF elements are organized as a hierarchical tree such that various parameters are grouped into associated, logical branches of the tree of possible parameters and options. The tree has a common root and branches are associated with certain enumerated groupings of related parameters that may be specified by a user/application in creating a job ticket. Some present-day printing systems include a print server or other print related computing devices that receive a JDF job ticket and process the JDF elements specified therein to directly control aspects of the print job.
The JDF specification defines a large number of printing parameters distributed through the logical branches of the JDF hierarchy. Some printing parameters may be specified in multiple branches of the JDF hierarchy. In some cases, a printing parameter may be equivalently specified using any of the multiple, duplicated JDF elements of the hierarchy. They may be duplicated because the parameters may be logically grouped in different portions of the tree hierarchy based on historical evolution of the JDF standards and also based on the application of JDF standards to legacy printing environments such as offset press shops as well as more recent digital press applications.
Some printing systems (e.g., older, legacy systems) provide no capability for directly processing JDF job ticket information. For example, a large number of existing printing systems support one or more Page Description Languages (PDLs) such as Postscript, PCL, etc., but provide no direct support for processing of JDF job tickets. Some of those existing printing systems support some job control features such as the Printer Job Language (PJL) originally specified by Hewlett Packard. For such printing systems devoid of direct support for processing of a JDF job ticket, the JDF must be translated into appropriate commands for a particular printer by a host based application (i.e., a print server JDF job ticket processor). However, given the variations of semantic meaning of JDF elements as defined for various models of printer by various vendors, it is an ongoing challenge to effectively process the JDF information contained in the job ticket. A custom coded translation process may be difficult to alter to adapt to the needs of a new printer or the definitions of a new vendor.